Posterior Dislocation Sternoclavicular Joint

The SC joint is supported by strong ligaments. Dislocations of the SC joint can occur due to injury to these strong ligaments. Dislocation of the sternoclavicular joint can be an anterior dislocation, which means the clavicle moves to the front or anteriorly (common) and this dislocation is benign and does not cause any problems in the majority of patients.  The posterior dislocation is dangerous, it can affect the trachea, esophagus, veins and arteries.  If you suspect posterior dislocation of the SC joint because of pain or swelling in this area, the CT scan is the best study for assessment of this joint and for establishing the diagnosis and for assessment of any associated injuries. In Figure 1, the CT scan showed posterior dislocation of the clavicle in a patient who sustained a shoulder injury 3 days prior to obtaining the CT scan. This injury was occult and not seen on the routine x-rays of the chest. The patient was evaluated because of swelling of the upper extremity. The Doppler showed DVT of the left upper extremity and a CT scan with contrast was ordered. Unexpectedly, the CT scan showed the clavicle to be posteriorly dislocated, compressing the vein and causing the DVT. Closed reduction with backup from a cardiac surgeon is the usual treatment, however, you may need to do open reduction in some cases with repair of the ligaments. Once you reduce the joint, the joint is usually stable. Posterior dislocation can be a difficult diagnosis. It could be associated with more serious problems such as dyspnea, dysphagia, tachypnea, and compression of the great vessels. Sometimes it may be associated with DVT of the upper extremity. The good news is that posterior dislocation is not common. On the other hand, the anterior dislocation is common, obvious bump, benign injury and does not affect the function. If you try to do a closed reduction on an anterior dislocation, you will not be able to maintain that reduction. On the other hand, posterior dislocation will be stable after reduction.